Cross posted to VMESA-L and LINUX-390. We are running a z990 with 4 z/OS LPARs and 1 z/VM LPAR for zLinux. Recently, while reviewing device definitions for a new IODF, we noticed some inconsistencies in the 3390 definitions for the z/VM LPAR, specifically that some devices were SHARED (others were not) and that some devices had MDC=DFLTON (others did not). This inconsistency was an oversight, however, after reviewing the V4R4 CP Planning and Administration Guide Chapter 22, the explanations of these parameters and the examples left us scratching our heads about what should be specified in the IODF. Obviously, the determination of the values for these parameters is dependent on how we plan to use the DASD, so ...
Normally, z/VM DASD is offline to the z/OS images, however, we plan to use z/OS to do full volume backups to tape of selected z/VM volumes containing minidisks used by zLinux images. We will use z/OS to do this because of existing very mature tape management procedures that will enable disaster recovery by rotating the tape volumes off site with absolutely no changes to any procedures. We understand that the zLinux image must be shut down to insure that all updates are "written" from zLinux, and then plan to FlashCopy the volume, ultimately using z/OS to perform a tape backup of the FlashCopy target volume. So, it would seem that the FlashCopy volumes need to be defined as SHARED and that MDC might not be relevant. What about "regular" volumes that are carved up into minidisks? It would seem that specification of MDC in the z/VM directory provides more flexibility than putting it in the IODF. The manual seems to say that hardware reserves will be issued only for full volume minidisks, which we do not expect to have. We would like to have the flexibility to move individual devices around between z/OS and z/VM, and FlashCopy source or target as needed, so we are looking for a consistent set of definitions to go in the IODF. Suggestions are welcome. Thanks for your advice. Chester Hood State of Tennessee 615-532-1781 [EMAIL PROTECTED] ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
